Yep, for me, it's a bit OP too. On the other hand, people will need to adapt to new rules, so less boring line-ups repeated 100x times.

Some time ago I was afraid about Fiendish Harpy being too OP. For some rulesets like Earthquake, Unprotected, Fog of War it is actually. It's a bit nerfed by introducing Furious Chicken because in most of the battles Harpy wastes 1-2 attacks for this Chicken. But.. Cursed Slimeball will remove the armor or even kill the Chicken so it would be useful to use both Cursed Slimeball + Fiendish Harpy (or any other monster with Opportunity).